The invention relates to a storage case for at least one data disk, in particular, a compact disc (CD) or a digital versatile disc (DVD), that stores digital information and is provided with a central opening, the storage case comprised of a base for receiving the data disc and a lid parallel to the base, wherein the base comprises a substantially rigid base plate and a support for the information disc that is provided at the base plate and is also rigid, a fastening zone arranged at the center of the base plate and con nected thereto by springy radial sections and having a centrally arranged rigid pressure element as well as tongues, distributed about the pressure element and securing the data disk positively and provided with integrally formed snap-on cams that project slightly past the edge of the opening of the data disk when resting on the support.
For storing such data disks, a variety of different storage cases are available on the market. The cases have in common that the data disks are fixed on a base by means of circularly arranged clamping elements that engage the central opening of the data disk and secure it in this way in a horizontal direction on the base. For fixation of the data disks in the vertical direction, snap-on cams of the clamping elements engage the central opening of the data disk. By applying a vertical pulling force on the data disk, the clamping elements are loaded such that when a sufficiently large force is reached they move elastically inwardly and release the CD. In particular in the case of data disks having a dual-layer configuration like digital versatile disks (DVD), this clamping technology has been found to be disadvantageous because the high removal forces, in particular in the case of improper removal, for example, when gripping only one side of the DVD, can cause destruction of the DVD.
For avoiding this problem, storage cases are disclosed in EP 0 789 914 B1 that enable the release of the data disk by one hand by actuating with a finger a centrally arranged mechanism that is of a simple configuration and is characterized by minimal removing forces acting on the data disk. This mechanism is comprised essentially of clamping elements attached to springy arms and provided with engagement means for the data disk, wherein the clamping elements by being pressed down together can be lowered through the central opening of the data disk. This lowering of the two clamping elements including the snap-on cams is realized along a circular path. When the engagement provided by the clamping elements is released upon reaching the required lowering travel, the data disk is lifted by means of a mechanism comprised of four springy supports to a level above the upper terminal position of engagement of the clamping elements. Reliable removal of the CD depends on the dexterity of the operator, since, for example, a pressure force that is not applied precisely centrally leads to a non-uniform compression of the clamping elements so that the data disk will assume a slanted position, will cant, and possibly cannot be removed easily.
A storage case of the aforementioned kind is disclosed in EP 0 896 719 B1 in which the release of the data disk is realized by pressing a finger onto a centrally arranged pressure element. The pressure element is comprised essentially of three spring arms projecting from a base inwardly and having a circular segment rigidly attached to their ends, respectively. The arms with the rigidly attached circular segments are inwardly connected in a pivotable way to a substantially triangular central part. For engaging the data disk snap-on cams are formed on the circular segments. For removing the data disk, the central part is pressed down so that the arms are compressed elastically and the circular segments attached to their ends will move downwardly on a circular path similar to EP 0 798 914 B1. The reliability of the removal action is however a problem. This is so because it cannot be excluded that upon restoring action of the radial arms the data disk is locked again because the arms follow the same circular path upon return movement. Moreover, it has also been found to be disadvantageous that the precise point in time of release of the data disks, i.e., the release of engagement, can be detected by the user only with difficulties so that it depends on the user's dexterity to correctly catch this point in time. Should the user release the central element too early, the central element will spring back in the upward direction with the data disk still being secured and not yet in the removable state.